Elekit TU-8340VK Review (Part 2): Could This Be Your Last Power Amplifier?

Drone camera shot of Elekit city. I told you the R-core power transformer was a beaut!

by Steve Graham

Of course you know I’m not going to answer the title question until the very end. So, you instant gratification types – I’m one of you – use your favourite scrolling digit and skip to the end, as long as you promise to come back and read the whole article.

Now that you’re back, I have a little housekeeping to do first. Victor Kung called me just after part 1 was posted and informed me that I had made a couple of errors. In my defence, Victor is a wellspring of knowledge which he is only too happy to share, but at times it bursts forth from him with such speed and enthusiasm that I couldn’t jot it all down. Anyway, here’s the correction: “He (Victor) ordered special production runs of Takman 2% carbon film resistors to replace the stock generic 5% resistors normally supplied by Elekit. As well, he ordered two expensive, custom Amtrans resistors for use in a critical power supply location.” Later on in part one I should have said, “The amp I built came with the stock Elekit output transformers, the 66 piece Takman 2% and two Amtrans 2W resistor option and eight Mundorf EVO Supreme caps.”

Victor also passed on concerns using the amp with KT150 tubes. He strongly recommends using tubes that have been tested for plate current (iP). Only tubes with an iP of less than 80 mA should be used as any that draw more than this might not bias properly. Those planning on using KT150s should have their tube dealer select ones to this spec. If you have questions, contact Victor for more details. In my time with the TU-8340VK, the semi-auto bias circuit has worked perfectly with all tubes from 6L6GC through to KT120.

System Particulars

This amp, like many (if not all) of the smaller Elekit amps, has a volume control. There is only one input, so I think most people will be using this amp with a line stage or full function preamp. That being said the volume control is handy for reviewers. I can change upstream components without having to power the amp down, by simply setting the volume to minimum while swapping input cables.

I benched my Arc Ref 3 line stage. In its place I used a couple of different Aikido line stages much like the ones I wrote about in my line stage series.

These Aikidos have fully optimized tube sets similar to my favourites covered in the 6DJ8 shoot out (1, 2).

I compared the TU-8340VK to my ARC Reference 110 power amp. “Isn’t that a bit unfair to compare the Elekit to the ARC?” you ask. Sure it is, but I believe the only way to evaluate a component’s value is to compare it to a known reference. It’s a facet of human nature that we’re always making comparisons. We do it automatically. “Is this cheeseburger as good as the last one I had?” “Does this $50 tube sound twice as good as the one I paid $25 for?” You know what I mean.

My PSB’s are a bit of a difficult load, but it isn’t a problem for the ARC with its four 6550s per channel and weighty output transformers. The PSBs are a 4 ohm load but a relatively easy 4 ohms. There aren’t any wild impedance swings or crazy phase angles that can give tube amps fits, yeah I read Stereophile. I’ll give the Elekit a listen with a pair of speakers that have tame, tube–friendly specifications in a follow-up. The Elekit has two output taps, 4 to 6.3 ohms and 8 to 16 ohms, so I say it’s fair game to try them with my PSB’s.

I used Tung-Sol reissue 12AT7W/6201 tubes for input and phase-splitting duties. ElectroHarmonix EL34 and 6550 tubes, along with some NOS GE 7581A (high-spec 6L6GC), tubes I’d been dying to try, rotated through the output sockets.

Listening to the Elekit TU-8340VK

I’m a firm believer that stereo electronics, especially tube gear, need a lot of break-in time. To expedite this I connected up my infrequently-used Aikido line stages and fed them and the TU-8340VK a CD on repeat. I loaded the output of the Elekit with 12 ohm, 20-watt resistors, so it could run through the night thus ensuring reasonable Domestic Harmony.

At about 20 hours into the break-in cycle I did a little listening, and to tell the truth music didn’t sound that great. I’ve been struggling with one particular line stage for a while, and the struggle isn’t over yet. Out with the fancy Aikido, in with the plain-Jane Aikido. This one, made mostly from of bits and pieces kicking around my shop, I’d built for myself after completing the above mentioned line stage series. It’s meant as a budget reference for reviewing purposes. It (plain-Jane) has been tube-rolled to the nth degree and utilizes an old but serviceable Alps Black Beauty stepped attenuator. The circuit board is dwarfed by two whopper Clarity Caps performing output duties. The rest of the parts are decent but not especially noteworthy. Plain-Jane sounds surprisingly good.

With Jane in control, I put on some Stevie Ray Vaughan. Something just seemed right about listening to Stevie through an amp with what are essentially 6L6GC’s in it. Wait, SRV was a Marshall guy and that means EL34’s. At any rate, it sounded darn good. The drum hits in the first 45 seconds or so of Couldn’t Stand The Weather were explosively rendered. The opening of this track, if I may digress, is good for choosing speaker polarity. Listen to the first minute of the track, reverse the polarity and listen to it again. Switch back and forth three or four times and you’ll likely hear one orientation sound more visceral than the other. About one and a half minutes into Little Wing I heard a hum, and started to panic thinking something in the system was amiss or a tube was about to go supernova. I hit pause on the CD remote, no hum. I backed up a bit, and there was the hum again. What I expect was a bit of guitar amp hum was audible for a few seconds. I’d never heard that before. All in all listening to SRV with this setup was a toe-tapping good time. The Elekit passes the PRaT on well, assuming the rest of your system, especially the preamp, has it. The tempo changes in SRV’s Pride and Joy were followed unerringly. The system – with either my ARC pair or the Elekit-Aikido pairing – doesn’t sound slow; the musicians don’t seem to trip over each other and drag the tempo down. Now I don’t listen at ear-splitting levels, but I’m not shy about cranking it up if warranted. I usually listen at noticeably louder than polite levels.

Most of the listening was done with my set of Electro-Harmonix 6550 tubes. The NOS GE 7581A tubes sounded great, but the E-H 6550’s worked just as well, too. I wasn’t that enamoured of the E-H EL34’s. They just sounded too polite; dynamically constrained and bass shy. Whichever tubes chosen, the Elekit’s semi-automatic biasing feature is slick – and very handy for a neurotic reviewer that likes to play tube jockey.

At this point I should tell you the TU-8340VK has a lot of gain. A line stage is not necessary to get this amp going. In fact, to get a more useful range on my line stage volume control I set the control on the TU-8340VK to about the 2 o’clock position. I’ve never been a fan of systems without an active preamp: they just don’t seem to have the drive and dynamics that a good preamp can bring to the party.

Next up was Loreena McKennitt’s The Mystic’s Dream from her The Mask and Mirror album. The small bell that’s heard throughout the track was clear as, well, a bell. Loreena’s voice is well rendered, not too dull, not too sibilant. The male voices on this track were delineated clearly too.

I apologize if I don’t get into enough detail about all of the nit-picking audiophile terms; soundstaging, microdynamics, tonal shadings, that sort of thing. In my opinion, you can over think things. With a set of no-nonsense Electro-Harmonix 6550 tubes installed, the TU-8340VK just seduced me in to relaxing and enjoying music. I guess that kind of says it all, but of course I’ll try to say more.

Line Stage Hijinks

I know I said I’d benched my ARC Reference 3 linestage, but I couldn’t resist giving it a try. It works best with balanced sources and power amps, in fact sometimes it sounds downright ugly with non-balanced connections to partnering components. With nothing to lose I disconnected the Aikido and replaced it with the Ref 3. I heard most of the improvements I normally hear when I put the Ref 3 back into my usual system. Well-layered and broader imaging, clearer highs, more nuanced mids and taught, well-defined bass were all there to be savoured. That a nearly base model TU-8340VK can delineate the improvement wrought by inserting the Ref 3 into the system is impressive indeed. Fancy Lundhal output transformers and Mundorf coupling caps should yield even better performance. The Mundorf upgrades are available at two performance (and price) levels. As mentioned earlier Victor shipped the less expensive of the two with my kit. I substituted them for the stock Panasonic caps closer to the end of the review process. I was prepared to leave the Ref 3 in the system. The Elekit revealed what it had to offer, so why deny myself, I thought? But then I found a snake in the garden.

The Ref 3’s compatibility issue with non-balanced amps had reared its humming head. There was a low level buzz present that was audible when close to the speakers if music wasn’t playing. Enter my secret weapon: a box I’d made with two small Lundahl transformers, to match the balanced output on the Ref 3 to an unbalanced input on a power amp. The hum was now gone, and all other attributes of the Ref 3 were present – except that the bass was slightly shelved down. The PRaT was still there in full measure but I missed that last bit of bass growl and rumble. The Ref 3 was again benched for the remainder of the review. Back to Jane, my fun, funky, frugal Aikido.

After the difficulty with the Ref 3, I was tired of listening to equipment so I just slid the Columbia SBM remaster of Kind Of Blue into the CD player. It was sublime. My connection to the music was better than I can recall it being on any previous listening.

Better sound with a little help from Germany?

Listening to the Mundorf EVO Supreme cap upgrade ($118 US)

I replaced the stock Panasonic caps with the more modestly priced of the two available Mundorf upgrades. It involved removing the main board from the chassis to perform the swap. If you’ve assembled the amp yourself, it’s quite straight forward. Budget about an hour and a half of sweat equity, but, also let the amp sit unpowered overnight to ensure the high-voltage filter caps have completely discharged before starting the upgrade process.

Audio memory is notably unreliable. We can all visualize the slow motion replay of a puck being tipped past a goalie, but the specifics of an audio event are much harder to recall. I let the amp run for another 5 or 6 days, 12 hours a day to let the new caps break-in a bit. The system had jelled and the Elekit with the Mundorfs installed had seemed to settle in, so I deemed it time to stop enjoying music and get down to the hard work of reviewing. The majority of listening, up to this point, was with the Electro-Harmonix 6550’s, a good value tube I’m quite partial to. The E-H 6550 occupied the sockets for the rest of the review.

All that being said, about audio memory being unreliable, the improvements wrought by the Mundorfs were not subtle, but all good. I’m sure if there were two TU-8340s side by side with the only difference being the stock caps and the base level Mundorf upgrade, I could hear the differences in an instant. The most notable aspect of the Mundorfs’ performance was better impulse response. This was most noticeable with percussion instruments. The initial hit of a drum stick on a cymbal was more startling. The initial tick of a stick hitting a wood block seemed more sharply defined. This on its own would be OK but what made it even better was the follow up, with what was more sustain; a clearer brassy sound of the shimmering cymbal and the ‘ock’ sound of the wood block. A pick dragged in a languorous manner across the strings of an electric guitar had more bite and clarity, but also seemed richer and took longer to fade out. Small bells and triangles had more initial strike, but also a longer lasting ‘ring’ and ‘ting’ to them. The increased detail did not seem to be accomplished at the expense of hyped-up high frequency response. Nor did this extra detail seem to slow the music down at all. The music, where appropriate, propelled itself along with its usual brio.

The Mundorfs didn’t make sibilant vocals (Peter Gabriel, Ms. McKennitt) sound any better, but they didn’t sound worse either. The sandpapery percussion on the SRV tracks still sounded a bit grating, but not any worse than before. The improvements were most noticeable at the higher frequencies but this extended all through the spectrum. Even tapped bass guitar strings had more startle and initial bite, followed up by better purr. The best part is all of this detail is not “thrust out” of the speakers at the listener, it just seemed to be laid out in front to be savoured. This sort of dramatic improvement usually has audiophiles chasing a new phono cartridge, expensive interconnects or possibly some NOS tubes. That this level of improvement can be had for $118 US (~$160 CDN) makes it a no-brainer choice. If your budget is tight don’t sweat it, stick with the stock caps. When funds are available, go for the Mundorfs and discover your amp all over again.

It probably doesn’t need stating, but I will anyway; the good vibrations I experienced with the Mundorfs on board were to a large extent attributable to the TU-8340VK. Audiophile capacitors, or any other fancy parts for that matter, won’t make a poor or mediocre circuit sound good. The Elekit is a fine amplifier to start with, and the Mundorfs provided that little bit extra enjoyment, at a very advantageous price/performance ratio.

Compared to the ARC Reference 110

I don’t know about you, but I find it much easier to hear a downgrade than an upgrade. Again, that’s human nature. We certainly feel the agony of going from a big seat on an airplane to a small one more sharply than the pleasure of going from small to big. Same thing with expensive ice cream, then eating the cheap stuff; or real maple syrup followed by maple flavoured syrup. So with that in mind, I played a track or two on the ARC, and then switched over to the Elekit. I’d then return to the Ref 110 for another track or two, then repeated them on the TU-8340VK.

To level the playing field, I used the volume control on the Elekit to set identical loudness when switching back and forth with the ARC Ref 110. I let both amps warm up for 30 minutes or so. The volume control on the line stage was untouched between identical tracks. Tracks used for the comparison were by Miles Davis, Loreena McKennitt, Steve Ray Vaughan, Lee Ritenour and Mark Knopfler.

In the bass, the ARC has better definition, extension and control. With the somewhat bruising load my PSB’s present, that’s not surprising. The Elekit wasn’t sloppy, but I could tell it was straining slightly, and a little out of its depth, though this was at quite loud sound levels. This is most noticeable on bass heavy tracks like Am I Wrong, from Lee Ritenour’s Six String Theory. The Elekit was still a lot of fun on this track, even if it wasn’t in perfect control. The Elekit doesn’t, nor do any tube amps in my experience, exhibit the dominatrix-like control over woofers the way a Bryston 4B or other herculean solid state amp does. I’ll report on amp differences in a follow up, to hopefully get a better handle on bass performance with a more tube-friendly speaker.

The midrange was very listenable on both amps. Though the ARC has a smidge more detail, it was in this part of the musical spectrum where the Elekit really gave the ARC a run for its money. Loreena McKennitt’s vocals on The Mystic’s Dream from the album The Mask and Mirror were presented clearly with both amps. The ARC better resolved Ms. McKennitt’s intake of breath that made the singer seem more alive and the listener closer to the performance.

With respect to treble performance, the gap widened between the two amps. The Elekit was good and in no way objectionable, but the ARC was more detailed and nuanced, but at the same time more relaxed. The percussion on So What from Miles Davis’ album Kind Of Blue was more detailed and just clearer through the ARC. The trumpet overtones had more ‘bite’ as well. My brother Bob played the trumpet (badly) through most of primary and all of secondary school, so I know how a trumpet can bite.

In the area of imaging, the ARC pulled away from the Elekit. The ARC had better layering and more specific instrumental and vocal positioning.

It’s not for naught that ARC calls their top of the line products HIGH DEFINITION®. But don’t think I’m belittling the performance of the Elekit. I don’t like ascribing numbers to performance, because I think it’s a one dimensional characterization. But if forced to I’d rate the TU-8340VK at six to seven out of ten, compared to the Ref 110. When you take into consideration that my ARC sold for $10,000 US new, and the TU-8340VK as reviewed sells for not quite $1,700 US (~$2,250 CDN), it’s a remarkable achievement for Elekit. And before you start tracking down a second-hand ARC, be aware that the cost of re-tubing a Ref 110 starts at about $600 CDN, and could easily run closer to $1,000 very quickly if choosing from more expensive offerings.

At no time listening to the Elekit did I feel I’d been cheated out of musical “goodness”. I never wanted to quickly disconnect it and go back to my ARC, the way I’ve wanted to rip some line stages out of my system that just got in the way of the music.

At this point I was wondering, and I’m sure you will be too, how much the Lundahl transformers and the pricier Mundorf caps might close the performance gap between the TU-8340VK and the Ref 110. If ordered together they represent an outlay of almost 70% of the base price of the amp, $863 US! I’d like to give these options a listen and hopefully I’ll get the opportunity to do that, soon.

Option Call

The TU-8340VK can be purchased in basic form, or with combinations of upgrade parts, should you wish.

That’s a lot of choice. If you purchase the basic amp and an inexpensive tube set, you’ll be up and running with a great sounding piece of gear. The upgrade resistor set would be nearly impossible to replace later so it’s one option box you might want to tick. The entry-level Mundorf package is a bargain for the improvement offered (see listening notes above), but it’s a fairly easy upgrade later on if your budget is tight to start. The expensive Mundorf package? I’ve not heard it yet, so I can’t comment on its cost/benefit worth. As far as tubes go, I wasn’t that enamoured of the E-H EL34. They just didn’t deliver the whomp and boogie I expect from a push-pull amp. The E-H 6550 tubes were better in this regard and are a good, not terribly expensive, place to start. A set of four can be had for about $250 CDN, tax and shipping in. I can’t comment on the E-H 12AT7 tubes. I used my own Tung-Sol reissue 12AT7W/6201 tubes – spares for my phono stage – and they didn’t give me a reason to try any others. A set of four Tung-Sols will set you back about $145 CDN, taxes and shipping in.

Worth springing for the Lundahl output transformers? We’ll answer this in the next installment. If your budget can stand the strain they’re supposed to be good, though I found the stock transformers performed admirably. Actually, at first sight I thought the stock OPTs looked a bit small for an amp that purports to output 50wpc. But they worked well even feeding my somewhat current hungry, moderate efficiency PSB’s. I think if you are planning to tube with 6L6GC’s, EL34’s, KT77’s, KT88’s or 6550’s, the stock transformers should do the job. If you’re tubing-up with KT120’s or KT150’s, and especially if your speakers are rated at 4 ohms, you might want to consider the Lundahls. If you want to upgrade to the Lundahls at a later date it’s an easy swap, no soldering and minimal disassembly required. About twenty minutes of your time is all it should take. Send me your stock transformers once you’ve made the swap, I’ll give them a good home. I’m always on the lookout for good, free, ‘iron’. If you are upgrading to the Lundahls, I’d deem it imperative to change the stock caps out at the same time – for at least the base level Mundorfs or other audiophile grade caps.

The Answer

Could this be your last power amp? If you plan to drive Wilsons, big planar dynamic, electrostatic or other current hungry, inefficient speakers, the answer is no. You probably already have a Krell, Levinson or other behemoth(s) for that chore. If you have speakers with a reasonable impedance, say 6 ohms or higher, and decent sensitivity (88db/w/m or better) in a midsize room or, smaller, less efficient speakers in a small room, then YES, this could be your last power amp. A big room with, say, a pair of Klipschorns or other ultra high-efficiency speaker could be a heavenly match for the TU-8340VK.

If you can’t or don’t want to assemble it yourself, get someone you trust to do it. I don’t think the Elekit TU-8340VK will disappoint, and in my estimation it’s very fairly priced for the performance it offers. It was an unalloyed treat assembling and listening to this amp. As for me, I already have my last power amp – but if I didn’t, “Honey, I neeeed to buy this,” would be heard at my house. On second thought, “Honeeey…..”

Final Thoughts

One problem though, how will Elekit follow this up? I’ve not heard their TU-8500 preamp, but I can’t help think that the TU-8340VK power amp might out-class it based on how good, hum aside, it sounded with my Ref 3. The hum was the fault of the Ref 3’s compatibility issues with non-balanced connections, not a fault within the Elekit; it was very quiet with my Aikido ‘Jane’ line stage. We can only look forward to what’s next from Elekit. (Next up is a highly anticipated replacement for the 300B SET TU-8300. -Ed.)

In a perfect world I could say, “Mr. Elekit please let me introduce you to Mr. Tubecad, father of the Aikido.”

You’ll want to install the tube cage when children, pets or other audiophiles are around. Just put a card or slippery piece of plastic between the head of the knurled screw and the cover to avoid scraping any paint off when installing and removing the screws

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Coming Soon:

I’ll cover listening with a different speaker and the amp in triode mode in a follow-up, along with the Lundahl OPT upgrade.

I’ve also lined up an array of various new production output tubes, and I’ll do a separate ‘shootout’ of these tubes, using the Elekit and another push-pull amp as well.

Big thanks to Victor Kung at vkmusic.ca for the ongoing loan of the amp.